In his luggage, they found a smoke grenade, three leather-coated Billy clubs, a collapsible baton, a full-face respirator, various knives, a hatchet, body bags, a biohazard suit, handcuffs, leg irons and a device to repel dogs.

Harris was wearing a bulletproof vest and flame retardant pants. He had recently been working in Japan.

It’s still not clear how he was able to board the plane there with the arsenal.

However, many of the items found in his checked bags were permissible according to TSA guidelines.

The LAPD bomb squad determined that the smoke grenade fell under the United Nations’ explosives shipping classification, meaning it is prohibited on board passenger aircraft.

Yongda Huang Harris in court

Harris was arrested and now faces one count of transporting hazardous materials. The charge carries a maximum penalty of up to five years in prison.

Authorities do not believe he is connected to a terrorist organization but his motives are unknown.

“As to why he had all the stuff, right now it’s still kind of a mystery, which kind of makes this case kind of intriguing.” Los Angeles Police Cmdr. Blake Chow told WBZ-TV Wednesday.

One of Harris’ neighbors in Dorchester is baffled by the discovery.

“They’ve been great neighbors, I see them occasionally,” he told WBZ.

“There’s never been any major activity coming from that house. Nice people… I’m honestly kind of surprised to hear about all of this.”